Hi Frank,
Unfortunately I am not able to access the page, it is giving me an internal error at the moment: https://i.imgur.com/0N6py1b.png
The plugin does not differenciate character lower-upper case, or accents – this is up to the database collation. By default, WordPress uses a character and accent insensitive collation “utf8mb4_unicode_ci” for all their tables.
If you can, please check and change your database collation accordingly, as well as the table collations. You might have to ask the server administrator for help, if you don’t know how, or don’t have direct access to the database.
There are bypass options within the plugin, that you can enable, but in most cases these does not help, as the table/db collation. You can try changing these options: https://i.imgur.com/gnz4u2v.png
It is very unlikely that it will work, but even if so, I still highly recommend changing the database/table collations.
